Flash reducer



Jr: 7 5 9.. m 2.. fw .r-Dn.-A Nmv mm K.R....v SH w. .ss Am bpm July 13, 1948. f

www

Patented July 13,l 1948 @Gm iii E lili-Ulli 2,444,951 FLASH REDUCER Leslie A. Skinner, Berkeley, Calif., assignor to United States of America as represented by the Secretary of War Application September 27, 1944, Serial No. 556,051

(Granted under the act of March 3, 1883, as

Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of -anyroyalty thereon.

This invention relates to a flash reducer for reduction of the propellent ash of rocket propelled projectiles. y

One of the major drawbacks to iiring rocket propelled projectiles, particularly from shoulder .L

to provide means to accomplish a substantial l reduction of the flash of rocket propelled projectiles.

A particular object of this invention is to pro- -vide an improved mounting arrangement for a container of flash-reducing material within the low pressure region of the combustion chamber 4rof the rocket projectile.

The specific nature of the invention as well as other objects and advantages thereof Iwill It is obviamended April 30, 1928; 370 o. G. '157) clearlyv appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig. 1 is a longitudinal-sectional view of the rear portion of a rocket motor embodying the invention, showing a container of flash-reducing material mounted in such motor.

Fig. 2 is an enlarged elevational view shown -partly in section, of one form of a container for a flash-reducing agent.

Fig. 3 is an enlarged elevational view partly in section of a modified form of a container for a flash-reducing agent.

There is shown in Fig. 1 in assembled relation a rocket projectile embodying this invention. The rocket projectile comprises a cylindrical housing I dening a combustion chamber 2. The rear end of housing I is shaped to define a constricted discharge passage 3 similar to a Venturi nozzle. A plurality of pivoted guiding :fins 4 are preferably provided at the rear end of housing I, being pivotally secured to an annular mounting ilange 5 which is in turn suitably secured to housing I. A tubular element I0 is provided extending through combustion chamber 2 concentrically therewith and terminating forwardly of discharge passage 3. While not limited thereto,

I impact with the target.

tubular member I0 preferably comprises a burster tube which communicates with the head of the rocket projectile and contains a high explosive sullicientlto` shatterA tube IIJ and housing `Ir upon A propellent charge I I is mounted within combustion chamber 2 and preferably. comprises a plurality of long cylindrical powder sticks I2 lying around tubular member I0. Powder sticks I2 are retained within combustion chamber 2 by suitable trap wires I3.

In accordance with this invention, a container 20 is secured to the extreme rear end of tubular member III. The container projects rearwardly towards discharge passage 3 but does not extend into such passage. The location of the container is particularly important as will be brought out ater.

Container 20 is preferably provided with thin ilexible wall sections 2|. As .shown in Fig. 2 wall sections 2| may be shaped to produce a Sylphon-like construction. In the modication yshown in Fig. 2, the container 20 'is secured to tubular member I0. by means of a plug I5 having a threaded shank I6 threa-dably engaging a suitable hole in tubular member I0 and an enlarged head vportion I1 around vwhich end of walls 2| of container 20 are bent and held in sealing .relationship against the end of tubular mem-V ber l0.

An alternative construction of the container is disclosed 'in Fig. 3 wherein. the container comprises a thin-walled cup-shaped member 22. The opened end of container 22 snugly surrounds the end of tubular member I0 .and is sealed there- ,to by any suitable means, as for example, by-weld- The container is lled with a suitableilashreducing agent preferably a liquid composition known as xylene. Xylene is known chemically as any one of the isomeric, colorless hydrocarlbons, CsH4(CHs)2, derivatives of benzine.. Such substance, when introduced in the form of a container through the hole 25. A sealing plug 26 is then inserted in the hole 25. Sealing plug 26 is of the blow-out type which will provide an effective seal for the flash-reducing agent 24 so long as the pressure conditions inside and out# side of the container are substantially equal. When the container 20 is positioned in a rocket projectile as described, i. e., in front of the discharge passage 3, the entire containerv will be located within a relatively low pressure region of the combustion chamber thus insuring that the thin-walled container will not be collapsed by the pressure developed within the combustion chamber.

Accordingly, during combustion of powder charge Il, the sealing plug 26 will be blown out of the container 20 by the relatively high exterior. pressure produced and operating on the thin walls of the container and thereafter the flashreducing agent 24 is forced out through opening 25 in container 20 into the gas discharge. The small size of opening 25 insures that flash-reducing agent 24 will be supplied gradually to the discharge gases, practically in the form of a spray, and thereby be effective for the entire burning time of the propellent.

It should be noted also that the forces produced by the initial rapid acceleration of the rocket projectile produce an inertia force of flashreducing agent 24 upon sealing plug 26 tending to breakout such plug. From the foregoing description, it is apparent that a simple and effective means for reduction of visible flash emerging from the nozzle of the rocket projectile is hereby provided.

I claim:

1. In a rocket projectile having a combustion c liagimzr and a constricted discharge passage communicating with said chamber, the improvement comprising a thin walled container 'secured in said chamber forwardly of said discharge passage, said container being filled with a flash-reducirigdagent, said container having an opening adjacent-`ii discharge passage and a blow-out sealing member secured in said opening whereby pressure developed within said combustion chamber will blow out said sealing member and disperse said flash-reducing agent thru said opening. i

2. In a rocket projectile having a combustion chamber and a constricted discharge passage communicating with said chamber, the improvement comprising a flexible wall, Sylphon type containerfsecured in said chamber forwardly of said discharge passage, said container being fllled with a flash reducing agent, said container chamber and a constrlate dwdishgggahssaga, Commissaris utliwsamnhanrer, a prenaient,... charge in'said chamber and a burster tube'iitdig thru the chamber and terminating forwardly of the discharge passage, the improvement comprising a thin walled container secured to the rear end of the burster tube, said container having a portion projecting rearwardly toward said discharge passage but terminating forwardly thereof, said container being filled with a ash-ggygiigjngwauglept, said container having an opening adjacent said discharge passage and a .blow-out sealing member secured in said opening whereby pressure developed within said combustion chamberwill blow out said sealing member and disperse said hash-reducing agent thru said opening.

4. In a rocket projectile having a combustion chamber and a constricted discharge passage `communicating with said chamber, a .propellent charge in said chamber and a burster tube extending thru the chamber and terminating forwardly of the discharge passage, the improvement comprising a thin walled cup-shaped container constructed to surround the rear end of said burster tube and secured thereto, thereby dening an enclosed space between the rear end of said burster tube and the interior walls of said container, the base of said container being disposed forwardly of said discharge passage, said enclosed space being filled with a flash-reducing agent, said container having 'a central opening in its base and a blow-out sealing member secured in said opening whereby pressure developed within said combustion chamber will blow out said sealing member and disperse said flash-redusing agent thru said opening.

5. In a rocket projectile having a combustion chamber and a discharge passage communicating with said chamber, the improvement comprising a container secured in said chamber forwardly of said discharge passage, said container being filled with a flash-reducing agent, said container having an opening adjacent said discharge passage and means normally sealing said opening, said sealing means being removable 'upon development of pressure Within said combustion chamber to allow said flash-reducing agent to disperse through said opening.

LESLIE A. SKINNER..

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,901,852 Stolfa et al Mar. 14, 1933 2,351,750 Fawkes June 20, 1944 FOREIGN PATENTS Number Country Date 29,292 Great Britain 1909 

